Electric furnace for the treatment of comminuted material



Aug. 24 1926.

J. J. NAUGLE ELECTRIC FURNACE FOR THE TREATMENT OF COMMINUTED MATERIAL 2 Sheets-Sheet 1 Original Filed April 21. 1923 a Mu VA m J 4 N A TTORNEY Aug. 24 1926; 1,597,208

JQJ. NAUGLE ELECTRIC FURNACE FOR THE TREATMENT OF COMMINUTED MATERIAL Original Filed April 21. 1923 2 51 1 41 2 j g i.

l I IIH' ll 4 47 ll 43 42 4/ 46 t &8 3 4s 92 44 4! 44 95 lNVEA/TOR JOHN J NAUGLE A TTORNEY Patented Aug. 24, 1926. i I g UNlTEDgsrATEs Joana. nations, or 3300mm, new YORK.

PATENT OFFICE.

ELECTRIC ACE FOR THE TREATMENT OI'COHMINUTED KATE BILL.

Application filed Api'ilfil, 1928, Serial No. 683,642. Renewed November 7,1925.

1 My present invention relates to electric rnaces, particularl but not exclusively, such as are intende for the treatment of comminuted carbonaceous or other materials, and aims to devise structures of the general character designated above which shall be simple in construction, which shall have few parts, and which shall be admirably designed to effect a regulated heattreatment of the materials intended to be treated in the furnace, for producing a final product having certain predetermined characteristics. Another object of the present invention is to devise structures of the general character specified above, which shall be certain and dependable in operation, which shall require little power for mechanical and heat generating purposes; which shallmake ample provision for the proper feeding of the material treated in said furnace and for the proper and efficient heating of such material during the time it is within the furnace; which shall make proper provision for current distribution in such a way as to most efficiently heat the material within the furnace; and which shall be capable of continuous, as distinguished from batch, operation.

A further object of the present invention is to devise furnaces of the general character specified above which shall permit the substantiallycontinuous production of material of a high degree of purity. In particular, if comminuted carbonaceous material, such as comminuted carbonized lignin residues, suitable for the preparation of highly activated decolorizing carbons, is

treated v in afurnace constructed in accordance with the principles of the present invention, the result is a remarkably pure carbon ofvery high conductivity correspond mg to a very high degree of activation and decolorizing power.

In the accompanying specification I shall describe, and in the annexed drawin show, an illustrative embodiment of the urnace of the present invention. It is, however, to be clearly understood that my invention is not limited to the specific embodiment thereof, herein shown and described for purposes of illustration only.

Referring to the drawing, wherein I have illustrated the aforesaid illustrative embodiment of the present invention:

Fig.1 is aside View, partly broken away, showlng the furnace comprising the aforetral orinner electrode which may be used with the aforesaid illustrative embodiment of the present invention? Figs. 5 and 6 are enlarged detail views of the electrode shown in Fig. 3 of the drawing; and i Fig. 7 is a side view, partly diagrammatic,

indicating one form of wiring circuit that may be used in connection with the aforesaid illustrative embodiment of the present invention.

Referring now to the aforesaidillustrative embodiment of the present invention, and more particularly to the drawing illustrating the same, the furnace comprising the aforesaid illustrative embodiment includes a casing generally indicated b reference character 10 and being preferab y of cylindrical. form. The casing10 comprises a plurality-of, here shown as three, sections 11,

12 and 13, these sections being made of metallic material, such as cast iron or steel,

.and serving as the external electrodes of the device, as subsequently described in greater detail.

At 14 I have shown an inlet provided with a suitable type of feeding means, such as the feed hopper generally indicated by'reference character 15, and including the feedf ing member 16 rotatably operated from any suitable source of power not here deemed necessary to be shown. At the outlet end of the machine, I have provided discharge hopper 17 communicating with a discharge chute 18 leading to an suitable bin or other stora e device in whic the finished material may e stored.

vided with flanged ends 19, 19; 20, 2,0; .and

21, 21, respectivel while the inner ends of,

between Each of the sections 11, 12 and 13 is pro-. 1

Suitably mounted for rotation within the casing is an inner electrode or shaft generally indicated by reference character 30. The shaft 30 is also divided into a series of, here shown as three, sections 31, 32 and 33, corresponding in number to the sections 11, 12 and 13 of the casing 10.

Each of the sections 31, 32 and 33 is provided with a series of conducting vanes or electrodes 34 which are preferably integral with the respective sections of the shaft 30. One end 35 of the shaft passes through a collar 36 forming an extension of the inlet 14 and preferably integral therewith. The other end 37 of the shaft 30 passes through a similar shaft 38 forming an extension of the outlet 17 and being preferably integral therewith. Preferably,the ends and 37 of the shaft 30 are insulated from the collars or extensions 36 and 38, respectively, so that "the shaft 30, and the sections 31, 32 and 33 of which the same is composed,

' "including also the conducting vanes or electrodes 34, are insulated from the casing 10, including the sections 11, 12'and 13 of which the same is composed, and including, also, the inlet 14 and the outlet 17.

The section 31 has a plurality offlanged portions 39 and 40 at its ends, while the section 32 is provided with the flanged end portions 41, 41, the section 33 being provided with the flanged portions 42 and 43 at its ends. Gaskets 44 are inserted between the opposed flanged end portions of the sections outer end, as indicated at 47, with a flang d sleeve or thimble 48 carried by the shaft 45 but insulated therefrom, all for a purpose :uilisequently to be described in greater de- Within the casing 10 are means generally lndlcated by reference character 50 for efficiently mixingflmd stirring the material treated in the-furnace, and for continuously advancing the same from one heating zone to the next during the treatment. While various devices may be employed for this purpose, I prefer to employ the means shown in the drawing, preferably Fig. 2 ofthe same, said means comprising a plurality of spiral elements 51 carried by the successive sections 31, 32 and 33 ofthe shaft 30, as by means of the supporting arms or brackets 52. As shown in Fig. 3 of the drawing, the arms or brackets 52 are supported at their inner ends 53 by the respective sections 31. 32 and 33 of the shaft 30, and carry atv their outer ends, indicated by reference character 54, the spiral elements 51 of the feeding means 50. It will also be noted that in the form illustrated herein by way of example, three spiral elements 51 are required for one complete turn of the spiral feeding means 50. Preferably, the spiral feeding means 50 and the arms or brackets 52 supporting the same, are of insulating material, or are covered with insulating material, so as not to serve as current car- "riers.

At 60 I'have shown an exhaust pipe communicating, by means of the connection pipes 61, 62 and 63, with the successive sections 11, 12 and 13 of the casing 10. The exhaust pipe 60 leads to a condenser and a water seal and thus serves as an exhau t for the gaseous products of combustion 01 reaction, or for any other 'gas which may be I present or which may be admitted to the charge within the furnace. At 70 I have indicated an inlet tube communicating by means of the sections 71, 72 and 73 with the successive sections 11, 12 and 13 of the easing 10. The gas inlet tube 70 may be connected with a source of supply of gas, preferably under pressure, intended to be ad mitted to the charge within the furnace. This gas may be either a neutral gas, to provide an inactive atmosphere within the furnace to lessen combustion, such as nitrogen gas, for example, or may be some other gas intended to take part in the reaction within the furnace, as to serve to eliminate 1n gaseous form certain undesirable impurities present in the charge of materlal present within the furnace.

At 81, 82 and 83 I have indicated sample test holes provided with the covers 84, 85 and 86, respectively, permitting the charge within each of the furnace sections 11, 12 and 13 to be tested from time to time, so as to determine the condition of the charge within the furnace at its difierentstage's of treatment.

In order to provide proper electrical connections for the electrodes comprising the case sections 11, 12 and 13, and the sections 31, 32 and 33 of the shaft 30 carrying the conducting vanes or electrodes 34, I may-"employ the means shown more clearly in Figs. 4 and 7 of.the drawing, and comprisingthe brushes 91, 92 and 93 contacting with the annular ends 39, 43 and 38 of the shaft sections 3.1 and 33, and the conducting thimble 47, respectively. The brushes 91, 92 and 93 are connected, by

means of the wires 94, 95 and 96, with one of the poles, such as the positive pole, of a direct current generator of suitable capacity, this generator being preferably provided with a shunt woun eld. The casing sections 11, 12 and 13 are connected, at

the points 11' 12' and 13', with the wires 97, 98 and 99 leading to the remaining Bpole, that is the negative pole, of the nut wound generator referred to, which gener-' ator isnot here deemed necessary to be shown. This system of electrical distribu-' tion is more particularly described and claimed in an ap lication, soon to be filed.

In, order to e ect a relative movement, such as a relative rotation of the cooperating setsof electrodes each comprising a casing section and a shaft section carr mg .the conducting vanes or electrodes 34,

relative movement, such as the spiral gear 100 cooperatin with the worm 101 driven from any suita le source of power not here deemed necessary to be shown. By the operative engagement of the worm 101 with the spiral gear 100, the shaft 30, com rising the sections 31, 32 and 33 carrying t e conducting vanes or electrodes 34, is rotated at" any desired or suitable speed relatively to the casing 10 comprising the casing sections 11, 12 .and '13. The'feedin "v means 50, in

the form of the pluralit of spiral feeding elements 51 described ve, being carrie by the shaft 30, will likewise be rotated with' the'same, and will thus serve to feed or ad- 'vance thematerial in the furnace during the treatment of the same and also to assist in thoroughly stirring and mixing such material.

The manner of assembling the above machine will be substantially clear from the foregoing description. The manner of operating the machine will'also be substantially clear from the foregoingdescri tion and may be briefly summarized as fo lows: In

commencin the o 'ration of the furnace, the materia to be reated, such as the comminuted carbonized lignin residues referred to, which residues are derived by carbonizing the cooking liquors'from the treatment of wood by the alkali (soda) process for producing wood ulp, is fed into the feed lopper 15 and is t ereupon continuously fed into the inlet 14 of the machine, by means of the rotating feeding element 16.: From the inlet 14 the material to be treated is fed into the first of the heating zones or reaction chambers, in this case the heating zone or reaction chamber within the casing section 11. I From the section 11 the material is fed into the successive heating zones orchambers within the successive casing sections 12 and 13, by means of the feeding.

means 50.

Taking, for example, the raw material specified above, or some-other comminuted carbonaceous material, such ,as spent de- M colorizing carbon, for the urpose of reparing therefrom a deco orizing car on characterized by a high de ree of activation and decolorizing power, t e former mater w any suitable means for effecting the desired,

rial, that is, the carbonized lignin residues referred to, may have an average analysis as follows:

Analysis of aom/miwuted carbonized I For. the best treatment of this material for, the intended purpose, the temperature in the first heating zone'or reaction chamber within the casin section 11 should be from about 800 to a but 1,500 0., corresponding to a articular current density; stem perature, rom about 600 to about 1,200 C., corresponding to a lower current density within the second heating zone or reaction a temperature of about-400 to about"600 0., corresponding to a still lower current density, should prevail'within the last'heating zone or reaction chamber within the remaining casing section 13. Ifthe apparatus is used for the revivification of spent decolorizing carbon, the temperaturejn the successive heating zones or reaction chambers within the respective casing sections 11,

12 and 13, should be about 600 (3., 500

and 400. C., respectively.

- By the o eration of the .gears 100 and 101, the sha 30, comprising the shaft sections 31, 32 and 33 carrying thtrconducti'ng vanes or,electrodes 34, is .caused to'rotate with respect to the sections 11, 12 and 13 of the casing. At the same time, the feedin means 50, also carried by the shaft 30 an the sections thereof, is caused-to rotate, thus chamber within the casing section 12; while causing the rotation and operation of the spiral feeding elements 51, which, together with theirsupporting arms 52, are insulated from the shaft 30 and'the sections 31 32 and 33 of the same, and also'from the conductin vanes or electrodes 34, as well as fromt e casing 10 and the casing sections 11, 12 and "13 of the casing 10. This relative rotation causes the material being treated, here designated by'reference character M, to be continuously fed from one heating zone or reaction chamber into the next, andto be thus subjected to electrical currents therein to the condition of small aggregates 1 or clinkers.

These willbe found to adhere to the sections 31, 32and 33 of the shaft 30, and to the conducting vanes or electrodes 3t carried thereby, as well as to the spiral feeding e'ements 51, and occasionally to the inner walls of the sections 11, 12 and 13 of the casing 10. v

The following is an average analysis of the final product resulting from the treatment of the raw material specified above in the above described form of furnace in accordance with the method outlined above.

Analysis of treated product.

Carbon 97.60 Ash 2.40 Analysis of ash.

Calcium 0.16 Sodium, Na O 0.35 Magnesium, MgO 0.16 Chlorides, (C1 0.06 sulphates (S0 -5 0.78 Silica, SiO, 0.50

Iron and alumina (fe O A1 0 0.39

2.40 The method is described and claimed in de-- tail in one of my copending applications filed of even date herewith, and the resulting product is likewise described and claimed in another of my copending applications filed of even date herewith.

The products of combustion are drawn off through the gas outlet by means of the connecting tubes 61, 62 and 63 communicating with the respective casing sections 11, 12and 13. The products of combustion or other gases of reaction are led to a condenser and a water seal. By means of the pipe having the connecting tubes 71, 72 and 73 communcating with the respective sections 11, 12 and 13 of the casing 10,, I may admit a suitable gas or gases to the various reaction chambers, such as nitrogen gas. if itis desired to minimize combustion and to carry on the reaction in a neutral or inactive atmosphere, or someother gas or gases which it may be desired to add and which will take part in the reaction, such as a gas calculated to remove in gaseousform bers from time to time to determine the condition of the material being treated at each of its stages. In this way I am enabled to regulate the speed of feeding the material into the machine, the rate at which the material should be fed through the machine, the rate at which the material should be mixed and stirred, and also the current densities which should best employed with the particular material being treated in the machine. The finished product passes out of the machine through the outlet 17 into the discharge hopper 18, leading to a bin or other suitable storage receptacle.

The advantages of theforegoing construction are numerous and of great practical importance. The furnace is simple in construction and has comparatively few parts, so that it may be readily built, set up and repaired if necessary. The furnace is so constructed as to effect an accurately regulated heat treatment of the materials intended to be treated in the same, for producing a final product having the desired characteristics. The furnace is also very certain and dependable in operation and requires comparatively little power for mechanical and heat generating purposes. The furnace also makes ample provision for the proper feeding and stirring of the material into, through and out of the same, and for the proper and graduated heating of the material during its treatment within the furnace. Provision is also made for accurate control and regulation of the feeding of the material into the machine through the machine, and .out of the same, and for theproper distribution of current through the material being treated. Furthermore, the furnace is capable of continuous, as distinguished from batch, operation. The resulting product is characterized by a high degree of purity, and, in the case where the raw material is either carbonized lignin residues or spent decolorizing carbon, such product is a remarkably pure and highly conductive decolorizing carbon characterized by a remarkably high degree of activation.

It may here be stated that the carbonized lignin residues referred to herein are the residues remaining after leaching the residues obtained by carbonizin the spent or used cooking liquors derive in the treatment of wood by the alkali (soda) process in the production of wood pulp; and that the terms activation and decolorizing, or their equivalents, as used in the specification and claims, include also deodorization, purification-and filtration. I

5 least, of the more readily volatile mineral constitutents of the material being treated to produce the product of the present invention. The product is thus of an unusually high degree of purity and of comparatively low specific gravity, weighing as low as about six, and up to about nine, pounds per cubic foot, whereas the raw material weighs 7 from about eighteen down to about ten pounds per cubicfoot. The product is also remarkably porous, of very uniform quality, and of ver high efliciency.

Since I pre er, also, that the carbon of.

thepresent invention shall, in the courseof its preparation, or otherwise, be deprived of no a substantial part of the fines or finer particles, the presence of which would tend to make the product unstable, to render it more combustible and to diminishits efficiency, which fines usually comprlse from abouttwenty, to about thirty, per cent of which tends to the weight of the material treated for the production of the product of the present invention, I obtain a product which may be made with a high yield, which is remarks 0 ably stable, which is less combustible than' other products of a similar nature, which shows a very low percentageofloss during its manufacture, and during its use for filtration and subsemiuent revivification, and

'e d a product of constantly increasing 0 ciency-during successive revivifications.

This reduction in the percentage of fines or finer. particles, may be effected by admitting air in regulated quantities .through the inlet pipe 70 and the branches 71, 72 and 73 of the same leading to the casing sections 11, 12 and13, res ctively.

'vary for the different chambers, since a chambers. The addition ofair, or its equivgreater degreeof combustion will generally desired in the first reaction chamber 11 7 than in the subsequent reaction chambers 12' and 13. It may here stated. that the heat ,,of' combustion resultmg of the fines refe to, assists in the treatment of the carbon and reduces the. amount of electric current which would otherwise -'be required to generate the desired degree of heat in each of the reaction alent, in regulated quantities, as above set forth, is found to have a very beneficial action upon .the product, accelerating thereaction and acting, 1n some-"way, to produce.

The amount ofair, or other oxi wing or. oxygen-containing gases, admitted to" the from the burningto the respective reaction chambers within the casing sections 11, 12 and 13, throughthe inlet pipe 70 and ,the branches 71, 72 and 73 of the same controlled by the respectice valves 71', 72 and 73". Steam in some way acts to accelerate the reaction,- as by breaklng down the mineral substances presthis way yielding a "product of increased porosity and purity. I may also add to the. charge within the furnace an addition agent, such as a fluoride, as sodium fluoride, for example, which would tend to combine with a part or all of the mineral impurities pres- .ent'in the raw material. being treated, in e ent in thecharge within the furnace, particularly silicious mineral impurities, such as silicaand silicates, to produce volatile compounds which would thus be eliminated from the final product.- Where the mineral impurity desired to be eliminated is silica, and the addition agent sodium fluoride, silicon fluorideis eliminated, with the produc-' tion of a soluble byproduct which may be eliminated by washingthe product. It may also be pointed out that the casing sections 11, 12 and 13 may be of different lengths, thus permitting the raw material to be subjected to treatment for different lengths of time in the respective reaction chambers, depending upon the particular treatment ticular chambers and under, the particular atmospheric conditions, as to air, steam and products of combustion or other reaction, or, otherwise, prevailingvin the particular reaction chambers. v

i For the purpose of comparing the specific resistivity, or conductivity, as desired, of the raw ,materialand of the final product, it may be stated that the total resistance of a mass of the raw material (in this case the carbonized lignin residues referred to) within a tube one inch long and one and seven-sixteenth inches in diameter, under a total pressure of one kilogram, was found to be about 167 ohms, corresponding to a resistance of about 6.28 ohms per cubiccentlmensionsand under a similar total pressure,, was found to be about 33.5 ohms, corre-- sponding to a resistance of about 1.26ohms per cubic centimeter. V

Another 'very valuable characteristicof the product of the present inventioniis that meter. The total resistance of a mass .of the final product within a tube of the same. di-

it is almost absolutely neutral, being neutral to phenolphthalein. This is probably the result of the manner in which the carbon is preferably produced, which consists in initially subjecting the raw material to a comparatively high temperature, which apparently converts the sulphates present in the raw material being treated, principally calcium and sodium sulphates, into sulphides, by the reducing action of the carbon, the sulphides, at a comparatively low temperature, being converted into the normal carbonates of calcium and sodium,'respectively, to yield a neutral carbon. If the temperature is again raised so as tobe comparatively high, the carbonates are apparently calcined and converted into the highly alkaline oxides. This is to be avoided since the neutralization of such an alkaline carbon by the addition of acid will tend to yield an acid carbon, which is highly undesirable, since acid carbons tend to invert sugar, where the carbons are used for the purification or filtration of sugar solutions, while alkaline carbons tend to form slimeswhich retard the rate of filtration or purification; while the carbon of the present invention, being, as it is, absolutely neutral, no slimes tend to be formed and thus a high rate of filtration or purification is possible, while the absence of acid in the carbon avoids the inversion of sugar if sugar solutions are comminuted material to purified or filtered through the product of the present invention.

What I claim as my invention is:

1. In an electric furnace for the treatment of comminuted, carbonaceous or other material, a substantially continuous cylindrical heating chamber having an inlet and an outlet and a plurality of heating zones of different heat intensities therein, electrodes mounted for rotation within said chamber, means secured to said electrodes for forcing material through said chamber, and means for separately regulating and controlling the heat intensities of said heating zones.

2. In an electric furnace-for the treatment of comminuted carbonaceous or other material, a heating chamber comprising a plurality of heating zones of different heat intensities, electrodes mounted for rotation within said chamber, means for charging said chamber, means operable by and upon rotation of said electrodes for feeding said material from one heating zone to another, and means for regulating the relative heat intensities of said heating zones.

3. In an electric furnace for the treatment of comminuted carbonaceous material, a cylinder providing a plurality of commu nicating heating zones, and separate means for heating each of said heating zones so as to provide heating zones of different heat intensities, and means secured to said heating means for forcing material through said cylinder.

4. vAn electric furnace for the treatment of comminuted carbonaceous material and the like, comprising a heating chamber having a plurality of zones of relatively varying intensity the inner wall of which chamber serves-as one electrode, and a rotatable electrode within said heating chamber, said electrode being so formed as to serve to advance said comminuted material during the relative rotation of said heating chamber and contained electrode.

5. An electric furnace for the treatment of comminuted carbonaceous material and the like, comprising a chamber having a plurality of communicating heating zones, said chamber having an inner wall serving as one electrode, an electrode within each of said heating zones, and means for effecting relative rotation of the last mentioned electrodes with respect to the chamber.

6. An electric furnace for the treatment of comminuted carbonaceous material and the like, comprising a chamber having a plurality of communicating heating zones, said heating chamber having an inner wall serving as one electrode, an electrode within each of said heating zones, and means for eiiecting relative rotation of said inner electrodes with respect to the chamber, each of said electrodes being so formed as to serve to feed comminuted material during the relative rotation of the electrode with respect to the chamber from one of said heating zones to another. v

7. An apparatus for obtaining'a highly activated decolorizing carbon from comminuted carbonaceous and like material, comprising an electric furnace having a plurality of communicating heating zones each including a plurality of cooperating electrodes, and means for passing electric currents of regulated different densities between the cooperating electrodes in the respective heating zones to provide a series of heating zones of different heat intensities.

8. An electric furnace for the treatment of comminuted carbonaceous and like material, comprising a plurality of communicat- 1 ing heating zones each including a plurality of cooperating electrodes, means for efiecting the advance of comminuted material from one heating zone to another, and means for passing electric currents of regulated different densities between the cooperating electrodes in the respective heating zones whereby a series of heating zones of different heat intensities are provided.

9. An electric furnace for the treatment of comminuted carbonaceous and like material, comprising a plurality of communicating heating zones, each including a plurality of cooperating electrodes, means for effecting relative rotation of certain of said 0 electrodes with respect tocertain others of said electrodes, certain of said :electrodes being so formed as to serve to advance comminuted material from one heating chamber I to another, and means for assing electric currents of regulated densities between the cooperating electrodes in the respective heating zones to provide a. series of heating zones of difl'erentheat intensities; 10 10. In an electric furnace for the treat- \ment of comminuted carbonaceous or other material, a substantially continuous heating chamber having a plurality of heating zones of different heat intensities therein, means for regulating the heat in each zone relative to other zones, and 'means for permitting the withdrawal of comminuted material from each of said heating zones for testing purs. I 11. In an-electric furnace for the treatment of comminuted carbonaceous or other material, a heating chamber comprising a luralit of heating zones of different heat intensities, and means for feeding comminuted material from one heating zone to another, in combination with means for permitting the withdrawal of comminuted material from each of said heating zones for testin purposes. 12 ln an electric furnace for the treatment of comminuted carbonaceous material,

a substantially continuous heating chamber, 7

and. means for heating said heating chamber, so as to provide heatin zones of different heat intensities, in combination with means for permitting the withdrawal of comminute'd material from each of said heating chambers for testing purposes.

13. An electric furnace for the treatment, of comminuted carbonaceous material and the like, comprising a plurality of comm'u-' nicating heating zones, each of said heat ingzones having a wall serving as one electrode, an electrode within each of said heating zones, and means for efiecting relative rotation of said inner electrodes with 'respect to the heating zones, in combination witlrmeans for permitting the withdrawal of comminuted material from each'of said heatin zones for testing purposes.

14; n electric furnace for the treatment of comminuted carbonaceous and like material, comprising a plurality of communicat ing heating zones each including a plurality of cooperating electrodes, and means for passing, electric currents of regulated densities between the. cooperating electrodes in the respective heatingzonesto provide a series of heating zones of difl'erent heat intensities, in combination with means for permit-ting the withdrawal of comminuted material from each of said heating zones for testing purposes.

15. In an electric furnace for the treatment of comminuted carbonaceous material or thelike, a chamber for receiving such maof different heat lntensities, certain of said electrodes serving to advance the material throughsaid chamber, in combination with means for admitting a gaseous reagent to each of said heating zones. 7

16. In an electric furnace for the treatment of comminuted carbonaceous material or the like, a plurality of communicatingv heating zones and means comprising a plurality of independently regulatable cooperating electrodes'in each of-s'aid heating zones for varying the heat in each of said zones relative-to the other zones, certain of said electrodes serving to advance the material 'terial, and a plurality of cooperating electrodes forming a lurality of heating zones through said heating zones, in combination with means for admitting and controlling the admissionof a gaseous oxidizing reagent to each of said heating zones.

17. An electric furnace for the treatment of comminuted carbonaceous material and the like, comprising a plurality of communicating heating zones, each of 'said heating zones having an inner wall serving as one electrode, an electrode within each of said heating zones, and means for efiecting-relative rotation of said last named electrodes with respect to the heatin zones, in-co nbination with means for a trolling the admission of a gaseous oxidizing agent and steam to each of said heating zones.

18. An apparatus for obtaining a highly activated decolorizing carbon from (301111111 nuted carbonaceous and like material, com .prising a cylinder having an electric furnace having a plurality of communicating heating zones, each includi a plurality of co: operating electrodes, an means for passing electric currents of regulated diiferent densities between the cooperating electrodes-in the res ective heating zones to provide a series of heating zones of different heat intensities, in combination with means for admitting air and steam, alternately, to said heating zones.

In testimony, whereof, I have signed my name tothis specification this 30th day of March, 1923. v 4 a JOHN J. NAUGLE.-

itting and con- 

